COPOLYMER LATEX, PAPER COATING COMPOSITION, AND COATED PAPER FOR PRINTING

PROBLEM TO BE SOLVED: To provide a copolymer latex being improved in the pick strength of coated paper and being excellent in production operability. SOLUTION: There is provided a copolymer latex which is prepared by the emulsion polymerization of a monomer mixture containing (a) 1 to 15 mass% ethylene-based unsaturated carboxylic acid monomer, (b) 85-99 mass% monomer other than the monomer (a) and copolymerizable with the monomer (a) (provided that (a)+(b)=100 mass%), wherein the ethylene-based unsaturated carboxylic acid monomer (a) contains (a-I) an ethylene-based unsaturated monocarboxylic acid monomer and (a-II) an ethylene-based unsaturated dicarboxylic acid monomer as essential components, and when taking the mass ratio of the ethylene-based unsaturated monocarboxylic acid monomer (a-I) to the total monomer mixture as A1 mass%, and the mass ratio of the ethylene-based unsaturated dicarboxylic acid monomer (a-II) to the total monomer mixture as A2 mass%, the relationship A1/A2≥2 is satisfied, and wherein the toluene insoluble part of the copolymer exceeds 96 mass%. COPYRIGHT: (C)2010,JPO&INPIT